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Please advise for 2k Generator and HMI lights

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jordan hill
Please advise for 2k Generator and HMI lights
on Nov 5, 2014 at 10:52:32 pm

I am looking to run a Altman 1.2K HMI and a altman 575watt HMI off a 2K generator. This should be enough in theory, but i am concerned whether 2K is going to be reliable enough to power these lights.


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Erik Anschicks
Re: Please advise for 2k Generator and HMI lights
on Nov 6, 2014 at 7:04:58 am

That's dicey, at best. Theoretically yes, it should hold if one does the math, but HMI's often use more juice when they initially fire than they do when they've settled down and running their constant draw. It's quite an inexact science, which is why you should be quite conservative when it comes to power estimates.

I would go with a higher capacity generator, I don't really see the need to lock yourself into a 2K one when bumping up to be safe wouldn't really cost much more.


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Mark Suszko
Re: Please advise for 2k Generator and HMI lights
on Nov 6, 2014 at 2:49:05 pm

You also don't say how far the cable runs have to be to keep the genny's noise away from the scene being shot. Longer cable runs add to the overall draw as well.


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Todd Terry
Re: Please advise for 2k Generator and HMI lights
on Nov 6, 2014 at 3:41:17 pm

Yeah, cutting it really close, as the other guys said.

Although mathematically they should be ok... like others have said an HMI draws more current when you strike it than when it's running... a lot more.

Ergo... if you want to try that, make sure you spark the 1200 first, and then after it gets cooking good (full power, and green glow disappears), turn it down as far as the ballast will allow. Then strike the 575. That will give you less of a total power spike than if you do it the other way around.

HMIs are notorious for needing really clean power... that'd be my biggest concern. When pushing the limits like that, I'd be prepared for one of them going dark if there are any juice fluctuations. I've been on many a shoot on locations with dirty power where we'd occasionally lose an instrument. It's not as big a deal as it used to be since most modern HMIs now are hot re-strike, but one of my older HMIs is not hot re-strike... and an accidental outage means a murderous 20-minute wait if I need to re-strike it. No one needs that.

T2

__________________________________
Todd Terry
Creative Director
Fantastic Plastic Entertainment, Inc.
fantasticplastic.com



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jordan hill
Re: Please advise for 2k Generator and HMI lights
on Nov 28, 2014 at 3:09:43 am

Hi everyone, thank you for taking the time to advise.

In the end we stuck with using the 1.2k HMI and stayed within the limits of the generator, and had no problems.

In the future i'll certainly push for a generator with more kva. The only reason we had the 2k generator was because it was free haha.


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